Incidence and risk factors for early postoperative stiffness after arthroscopic rotator cuff repair in patients without preoperative stiffness.

The purpose of this study was to investigate the incidence and risk factors of early postoperative stiffness in patients without preoperative stiffness undergoing isolated arthroscopic rotator cuff repair (ARCR). Two hundred seventy-four patients who underwent primary ARCR were included. At 3 months after surgery, criteria for shoulder stiffness was set as follows: (1) passive forward flexion < 120˚, or (2) external rotation at side < 30˚. Patients with preoperative stiffness or who underwent additional procedures were excluded. Patients-related, radiological (muscle atrophy and fatty infiltration), and intraoperative (tear size, repair techniques, number of anchors used, and synovitis scores) risk factors were analyzed. Univariate and multivariate analyses were used to identify risk factors for postoperative stiffness. Thirty-nine of 274 patients (14.2%) who underwent ARCR developed postoperative stiffness. Univariate analyses revealed that early postoperative stiffness was significantly associated with diabetes mellitus (p = 0.030). However, radiological and intraoperative factors did not affect postoperative shoulder stiffness (all p > 0.05). Multivariate analyses revealed early postoperative stiffness was significantly associated with diabetes mellitus and timing of rehabilitation (p = 0.024, p = 0.033, respectively). The overall incidence of early postoperative stiffness following isolated ARCR in patients without preoperative stiffness was 14.2%. Diabetes mellitus and timing of rehabilitation were independent risk factors for early postoperative stiffness following ARCR.

Study on the effects of arm abduction angle and cushion support during sonographic examination on the stiffness of supraspinatus muscle of sonographers using shear wave elastography.

OBJECTIVES: The incidence of work-related musculoskeletal disorder remains high in sonography. The aims of this study are to determine the changes in muscle stiffness with different arm abduction angles, and to investigate the effect of cushion support on reducing muscle load in the supraspinatus when sonographers scan with the arm abducted to different angles. METHODS: This is a prospective crossover study. Twenty-three healthy female subjects aged between 20 and 23 years were included. Subjects were instructed to simulate performing standardized abdominal ultrasound scans. The changes in muscle stiffness of supraspinatus, measured as shear modulus, at rest and at 30°, 45°, and 60° arm abduction angles with and without cushion support were evaluated using shear-wave elastography. Styrofoam support was used for the cushion support. RESULTS: Mean shear moduli of supraspinatus were 27.77 ± 5.84 kPa at rest and 41.63 ± 7.09 kPa, 63.88 ± 14.43 kPa, and 89.76 ± 16.55 kPa for 30°, 45°, and 60° arm abduction respectively, which corresponds to 53%, 116% increase in muscle stiffness when scanning arm abducted from 30° to 45° and 60° (p < .001). After applying cushion support, shear moduli dropped to 24.04 ± 5.60 kPa, 31.98 ± 6.06 kPa, 37.47 ± 5.61 kPa for arm abducted to 30°, 45°, and 60° respectively (p < .001). The muscle stiffnesses between 30° abduction without support and 60° abduction with support had no significant difference (p > .05). CONCLUSIONS: Muscle stiffness of supraspinatus increased with increasing arm abduction angle during ultrasound scanning. Utilizing cushion support underneath the arm was effective in reducing muscle stiffness in supraspinatus. Our results provide scientific justification on postural modifications for sonographers.

Injection of Micronized Human Amnion/Chorion Membrane Results in Increased Early Supraspinatus Muscle Regeneration in a Chronic Model of Rotator Cuff Tear.

Surgical repair of severe rotator cuff tear often results in retear due to unaddressed muscle degeneration. The objective of this study was to test the regenerative potential of micronized dehydrated Human Amnion/Chorion Membrane (dHACM), in a clinically relevant delayed reattachment model of rotator cuff repair. Micronized dHACM was injected into rat supraspinatus muscle during tendon re-attachment surgery, three weeks after original tendon injury. One week after material injection, inflammatory and mesenchymal stem cell infiltration into supraspinatus muscles was assessed via flow cytometry. Histological methods were utilized to assess structural and regenerative changes in muscle one and three weeks after material injection. Micronized dHACM injection resulted in increased M1-like macrophages (17.1 [Formula: see text] fold change over contralateral controls) and regenerating muscle fibers (4.3% vs 1.7% in saline treated muscles) one week after injection compared to saline treated muscles. Tendon reattachment itself exhibited intrinsic healing in this model, demonstrated by a general return of muscle weight and reduced fibrosis. Our results indicate that injection of micronized dHACM may initiate an inflammatory response in degenerated muscle that promotes early muscle regeneration, and that our animal model may be a suitable platform for studying treatments in muscle at early timepoints, before intrinsic healing occurs.

Corticosteroids or platelet-rich plasma injections for rotator cuff tendinopathy: a randomized clinical trial study.

BACKGROUND: Studies evaluating the role of both corticosteroids and platelet-rich plasma (PRP) in the treatment of rotator cuff (RC) tendinopathies have been contradicting. We compared structural and clinical changes in RC muscles after corticosteroids and PRP injections. METHODS: This is a randomized double-blind clinical trial. All individuals with diagnosis of RC tendinitis during 2014-2017 were considered. Individuals were randomly allocated to either receive PRP or corticosteroids. Overall, 3cc of PRP was injected within the subacromial joint and another 3cc was injected at the site of the tendon tear, under the guide of sonography. For the corticosteroid group, 1cc of Depo-medrol 40mg and 1cc of lidocaine (2%) was injected within the subacromial joint. RESULTS: Overall, 58 patients entered the study. Comparison of pain, range of motion (ROM), Western Ontario RC (WORC), Disability of Arm-Hand-Shoulder (DASH) scores, and supraspinatus thickness showed significant improvement during follow-ups in both groups (p<0.05). During 3 months of follow-up, pain improvement was significantly better within the PRP group during (from 6.66±2.26 to 3.08±2.14 and 5.53±1.80 to 3.88±1.99, respectively; p=0.023). Regarding ROM, the PRP group had significant improvement in adduction (20.50°±8.23° to 28°±3.61° and 23.21°±7.09° to 28.46°±4.18° for the PRP and corticosteroid groups, respectively; p=0.011) and external rotation (59.66°±23.81° to 76.66°±18.30° and 57.14°±24.69° to 65.57°±26.39°, for the PRP and corticosteroid groups, respectively; p=0.036) compared to the corticosteroid group. CONCLUSION: We found that PRP renders similar results to that of corticosteroids in most clinical aspects among patients with RC tendinopathies; however, pain and ROM may show more significant improvement with the use of PRP. Considering that the use of corticosteroids may be contraindicated in some patients and may be associated with the risk of tendon rupture, we suggest the use of PRP in place of corticosteroid-based injections among patients with RC tendinopathy. TRIAL REGISTRATION: Clinical trial registration code: IRCT201302174251N9.

Rotator cuff anchor repair: Histological changes associated with the recovering mechanical properties in a rabbit model.

Rotator cuff anchor repair is an increasingly common surgical procedure but the failure rate remains high. In order to improve surgical outcomes, a better understanding of postrepair histological and cellular responses at the tendon-bone attachment site (enthesis) is needed. We examined operated shoulders from 42 New Zealand female white rabbits. The animals underwent unilateral supraspinatus detachment followed by anchor repair a week later. To assess enthesis reformation, fibrocartilage staining area and the number of chondrocytes or nonchondrocytes were quantified at 0, 1, 2, and 4 weeks postrepair. Using linear regression, we correlated these results with the load to failure and stiffness recorded during mechanical testing of the tendons. Fibrocartilage staining and chondrocyte number increased during the first 2 weeks of enthesis formation. Between 2 and 4 weeks, fibrocartilage staining plateaued while chondrocyte number decreased. The presence of nonchondrocytes remained similar between 0- and 1-week postrepair but then decreased abruptly at 2 weeks. There was a linear correlation between fibrocartilage staining area and load to failure as well as stiffness. Nonchondrocyte number negatively correlated with stiffness. Early plateau of fibrocartilage staining and decrease in chondrocytes between 2 and 4 weeks postrepair suggest a blunted enthesis formation response in our animal model.

Do Relaxation Exercises Decrease Pain After Arthroscopic Rotator Cuff Repair? A Randomized Controlled Trial.

BACKGROUND: Pain after rotator cuff repair is commonly managed with opioid medications; however, these medications are associated with serious adverse effects. Relaxation exercises represent a potential nonpharmacologic method of pain management that can be easily implemented without substantial adverse effects; however, the effects of relaxation exercises have not been studied in a practical, reproducible protocol after arthroscopic rotator cuff repair. QUESTIONS/PURPOSES: (1) Does performing relaxation exercises after arthroscopic rotator cuff repair (ARCR) decrease pain compared with standard pain management medication? (2) Does performing relaxation exercises after ARCR decrease opioid consumption? (3) What proportion of patients who used the relaxation techniques believed they decreased their pain level, and what proportion continued using these techniques at 2 weeks? (4) Does performing relaxation exercises after ARCR affect shoulder function? METHODS: During the study period, 563 patients were eligible for inclusion; however, only 146 were enrolled, randomized, and postoperatively followed (relaxation group: 74, control group: 72); 68% (384 of 563) of patients were not contacted due to patient and research staff availability. Thirty-three patients were unenrolled preoperatively or immediately postoperatively due to change in operative procedure (such as, only debridement) or patient request; no postoperative data were collected from these patients. Follow-up proportions were similar between the relaxation and control groups (relaxation: 80%, control: 81%; p = 0.90). The relaxation group received and reviewed educational materials consisting of a 5-minute video and an educational pamphlet explaining relaxation breathing techniques, while the control group did not receive relaxation education materials. Patients recorded their pain levels and opioid consumption during the 5 days after ARCR. Patients also completed the American Shoulder and Elbow Surgeons shoulder score preoperatively and 2, 6, 13, 18, and 26 weeks postoperatively. Linear mixed models were created to analyze postoperative pain, opioid consumption measured in morphine milligram equivalents (MMEs), and shoulder function outcomes. A per-protocol approach was used to correct for patients who were enrolled but subsequently underwent other procedures. RESULTS: There was no difference in pain scores between the relaxation and control groups during the first 5 days postoperatively. There was no difference in pain scores at 2 weeks postoperatively between the relaxation and control groups (3.3 ± 3 versus 3.5 ± 2, mean difference -0.22 [95% CI -1.06 to 0.62]; p = 0.60). There was no difference in opioid consumption during the first 5 days postoperatively between the relaxation and control groups. The use of relaxation exercises resulted in lower 2-week narcotics consumption in the relaxation group than in the control group (309 ± 241 MMEs versus 442 ± 307 MMEs, mean difference -133 [95% CI -225 to -42]; p < 0.01). Sixty-two percent (41 of 66) of patients in the relaxation group believed the relaxation exercises decreased their pain levels. Fifty-two percent (34 of 66) were still performing the exercises at 2 weeks postoperatively. During the 6-month follow-up period, there was no difference in shoulder function between the relaxation and control groups. CONCLUSION: The preoperative administration of quick, basic relaxation exercises allowed patients to use appreciably lower opioid analgesic doses over the first 2 weeks after ARCR, without any worsening of pain scores. We consider this result promising but preliminary; it is possible that a more intense mindfulness intervention-the one we studied here was disseminated using only a 5-minute video-would deliver reductions in pain and further reductions in opioid usage. LEVEL OF EVIDENCE: Level II, therapeutic study.

Should Exercises be Painful or not? Effects on Clinical and Experimental Pain in Individuals with Shoulder Pain.

Exercise can reduce pain, however the effect of painful versus non-painful exercises is uncertain. The primary aim of this randomized crossover study was to compare the effect of painful versus nonpainful isometric shoulder exercises on pain intensity after exercise in individuals with rotator cuff-related shoulder pain. Secondary exploratory aims were to describe the effects on pressure pain thresholds (PPTs), conditioned pain modulation (CPM) and muscle strength. On separate days, 35 individuals performed painful isometric shoulder exercises (external rotation; 20% above pain threshold), nonpainful isometric shoulder exercises (external rotation; 20% below pain threshold), and a rest condition, in randomised order. Shoulder pain intensity, PPTs, CPM, and external rotation strength were assessed before, immediately after and 45 minutes after conditions. No significant differences were observed between painful and nonpainful exercises. Visual analogue scale scores increased immediately after both painful and non-painful exercises compared with rest (P = .047, partial ƞ2 = .07), but were similar to preexercise levels after 45 minutes. No changes in PPTs, CPM, or muscle strength after exercises compared with rest were observed. Painful and non-painful isometric exercises caused a moderate but short-lasting increase in shoulder pain in individuals with RCRSP. Isometric exercises had no effect on pain sensitivity and shoulder muscle strength or CPM. PERSPECTIVE: This study evaluated for the first time in individuals with rotator cuff-related shoulder pain the effects of painful versus non-painful isometric exercises on different pain-related outcome measures. Both painful and non-painful isometric exercises caused a moderate but relatively short-lasting increase in shoulder pain in individuals with rotator cuff-related shoulder pain. Trial registration number: (ClinicalTrials.gov) NCT03675399.

Differences in supraspinatus occupation ratio between the symptomatic, the contralateral asymptomatic shoulder and control subjects: A cross-sectional study.

ABSTRACT: The relationship between supraspinatus tendon thickness and the acromiohumeral distance (AHD) at both rest position and shoulder elevation is still to be explored in those with chronic shoulder pain. The aim is to compare supraspinatus occupation ratio (OR) at 0° and 60° of shoulder elevation measured by ultrasound imaging in the symptomatic shoulder, the contralateral asymptomatic shoulder and in healthy subjects. This was across-sectional, observational study. A sample of 56 participants with subacromial pain syndrome in their dominant arm was recruited in 3 different primary care centres. Forty participants without shoulder pain were also recruited. The AHD at 0° and 60° of active shoulder abduction as well as the supraspinatus tendon thickness were measured by ultrasound in these groups. Supraspinatus OR at 60° was significantly greater in symptomatic compared to asymptomatic shoulders (P = .04) and healthy shoulders (P = .008). The percentage of change in supraspinatus OR from rest position to 60° was also greater in symptomatic shoulders when comparing with asymptomatic (P = .01) and healthy shoulders (P = .03). No other statistically significant differences for the rest of comparisons were found. Supraspinatus OR may explain shoulder pain in chronic conditions. Further studies at acute and chronic conditions after a physiotherapy treatment are needed to explore its usefulness in clinical practice.

In Vivo Imaging of Fibroblast Activity Using a 68Ga-Labeled Fibroblast Activation Protein Alpha (FAP-α) Inhibitor: Study in a Mouse Rotator Cuff Repair Model.

BACKGROUND: Rotator cuff repair site failure is a well-established clinical concern. Tendon-to-bone healing is initiated by inflammatory mediators followed by matrix synthesis by fibroblasts. The kinetics of fibroblast accumulation and activity are currently poorly understood. METHODS: Ninety-six mice underwent supraspinatus tendon repair. Six were used for imaging using a novel 68Gallium (Ga)-labeled fibroblast activation protein alpha (FAP-α) inhibitor and positron emission tomography-computed tomography (PET/CT) at days 0 (before surgery), 3, 7, 14, and 28. Sixty-eight animals were divided into 4 groups to be evaluated at 3, 7, 14, or 28 days. Twenty-two native shoulders from mice without surgery were used as the control group (intact tendon). Six animals from each group were used for histological analysis; 6 from each group were used for evaluation of fibroblastic response-related gene expression; and 10 mice each from the intact, 14-day, and 28-day groups were used for biomechanical testing. RESULTS: There was minimal localization of 68Ga-labeled FAP-α inhibitor in the shoulders at day 0 (before surgery). There was significantly increased uptake in the shoulders with surgery compared with the contralateral sides without surgery at 3, 7, and 14 days. 68Ga-labeled FAP-α inhibitor uptake in the surgically treated shoulders increased gradually and peaked at 14 days followed by a decrease at 28 days. Gene expression for smooth muscle alpha (α)-2 (acta2), FAP-α, and fibronectin increased postsurgery followed by a drop at 28 days. Immunohistochemical analysis showed that FAP-α-positive cell density followed a similar temporal trend, peaking at 14 days. All trends matched closely with the PET/CT results. Biomechanical testing demonstrated a gradual increase in failure load during the healing process. CONCLUSIONS: 68Ga-labeled FAP-α inhibitor PET/CT allows facile, high-contrast in vivo 3-dimensional imaging of fibroblastic activity in a mouse rotator cuff repair model. CLINICAL RELEVANCE: Noninvasive imaging of activated fibroblasts using labeled radiotracers may be a valuable tool to follow the progression of healing at the bone-tendon interface.

Arthroscopic rotator cuff repair in patients over 70 years of age: a systematic review.

BACKGROUND: Failure of conservative treatment in patients over 70 years of age with a rotator cuff tear makes surgery a possible option, considering the increase in life expectancy and the high functional demands of elderly patients. The purpose of this systematic review of the literature was to evaluate the subjective and objective outcomes after arthroscopic rotator cuff repair in patients over 70 years of age. METHODS: A systematic review was performed to identify all the studies reporting subjective and objective outcomes in patients aged 70 years or older undergoing arthroscopic rotator cuff repair. Constant Murley Score (CMS), visual analog scale (VAS), American Shoulder and Elbow Surgeons Score (ASES), and Simple Shoulder Test (SST) were used to detect any clinical improvement after surgery. Retear and satisfaction were also analyzed. RESULTS: Out of 941 studies identified, only 6 papers have been included in the review. All studies reported improvements in postoperative functional outcome scores that exceed the minimal clinically relevant difference. The mean retear rate amounts to 21.9%, which is in line with the failure rate of rotator cuff repair in general population. Moreover, postoperative satisfaction is very high (95%). CONCLUSION: This systematic review suggests that arthroscopic rotator cuff repair in patients over 70 years of age could be a valid treatment option after failure of conservative approach. LEVEL OF EVIDENCE: 4 Trial registration The study was registered on PROSPERO (registration ID: CRD42018088613).

Biceps tenotomy versus tenodesis for lesions of the long head of the biceps tendon: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Biceps tenotomy and biceps tenodesis are 2 most common surgical procedures for long head of the biceps tendon (LHBT) pathology, but debate still exists regarding the choice of treatment. This meta-analysis was conducted to compare clinical results between tenotomy and tenodesis for the treatment of lesions of LHBT. It was hypothesized that there is no difference in outcomes of tenotomy and tenodesis for lesions of LHBT. METHODS: A comprehensive search of literature published between 1980 and April 2020 was performed using MEDLINE, EMBASE, Web of Science, and the Cochrane Library databases. Randomized controlled trials (RCTs) comparing tenotomy and tenodesis for LHBT lesions were included. The primary outcomes were Constant score and Popeye deformity. The secondary outcomes included the American Shoulder and Elbow Surgeons (ASES) score, visual analog scale (VAS) for pain, muscle strength, cramping pain, and operative time. For primary outcomes, trial sequential analysis (TSA) was conducted to reduce the risk of random errors and the GRADE (grading of recommendations, assessment, development, and evaluations) approach was used to assess the quality of the body of evidence. RESULTS: A total of 9 RCTs were included. In pooled analysis, statistical significance was observed in the Constant score (mean difference [MD], 1.59; 95% confidence interval [CI] 0.04-3.14; P = .04), Popeye deformity (risk ratio [RR], 0.33; 95% CI, 0.22-0.49; P < .00001) and operative time (MD, 9.94; 95% CI 8.39-11.50; P < .00001). However, there were no significant differences between the tenodesis and tenotomy in ASES score (P = .71), VAS for pain (P = .79), cumulative elbow flexion strength (P = .85), cumulative elbow supination strength (P = .23), and cramping pain (P = .61) TSA revealed that the results for Constant score was inconclusive. CONCLUSION: For the treatment of LHBT lesions, with the exception of constant score, there was no significant benefit of tenodesis over tenotomy. Although tenotomy is affected by a higher risk of Popeye sign, it is more timesaving.

Effectiveness of Focused Shockwave Therapy versus Radial Shockwave Therapy for Noncalcific Rotator Cuff Tendinopathies: A Randomized Clinical Trial.

BACKGROUND: The superiority of focused shockwave therapy (F-SWT) versus radial shockwave therapy (R-SWT) for treating noncalcific rotator cuff tendinopathies remains controversial. This study is aimed at comparing the effectiveness of F-SWT versus R-SWT for the management of noncalcific rotator cuff tendinopathies. METHODS: A total of 46 patients affected by noncalcific rotator cuff tendinopathies were randomly divided into 2 groups of 23 individuals. Patients in group A received 4 sessions of F-SWT, while patients in group B were treated by 4 sessions of R-SWT. In each session, mean energy flux density (EFD) for F-SW 3000 shots was 0.09 ± 0.018 mJ/mm2 with 5.1 ± 0.5 Hz, while average pressure for R-SW 3000 shots was 4.0 ± 0.35 bar with 3.2 ± 0.0 Hz. Pain level and shoulder function were assessed with the numerical rating scale (NRS) and Constant-Murley Scale (CMS). The primary endpoint was the change in the mean NRS pain score from baseline to 24 weeks after the intervention. Secondary endpoints were changes in the mean NRS pain scores at all other follow-up points, changes in the mean CMS scores, and radiographic findings. RESULTS: There were no significant differences between the two groups regarding NRS pain score and CMS score within 24 weeks after intervention (all p > 0.05). However, F-SWT resulted in significantly lower NRS compared with R-SWT at 24 weeks and 48 weeks after treatment (2.7 ± 1.0 vs. 4.5 ± 1.2 and 1.4 ± 1.0 vs. 3.0 ± 0.8, respectively, all p < 0.001). Similar results were found in CMS changes and radiographic findings. CONCLUSIONS: Both F-SWT and R-SWT are effective in patients with noncalcific rotator cuff tendinopathy. F-SWT proved to be significantly superior to R-SWT at long-term follow-up (more than 24 weeks). This trial is registered with ChiCTR1900022932.

Factors affecting the onset and progression of rotator cuff tears in the general population.

While previous studies have revealed factors affecting the progression of rotator cuff tear (RCT), none have yet described factors affecting its onset. The purpose of this longitudinal observational study was to analyze factors affecting the RCT onset and progression in the general population. The present study included 185 shoulders from 93 participants who completed all the examinations in both 2012 and 2017. Participants received a questionnaire with age, gender, arm dominance, and presence of pain at rest, in motion, and at night. The range of motion (ROM), simple shoulder test (SST) were also examined. Anteroposterior radiograph of the shoulder joint was performed to evaluate the degree of osteoarthritic changes by the Samilson-Prieto (S-P) classification. The degree of RCT was examined by ultrasonography. There were 132 shoulders without RCT and 53 with RCT in 2012. RCT occurred in 21 of 132 shoulders, and the factor affecting the RCT onset was S-P grade 2 osteoarthritic change in 2012 (odds ratio [OR] 10.10). RCT progressed in 22 of 53 shoulders, and the factor affecting RCT progression was the presence of motion pain in 2012 (OR 13.76). These results added new knowledge regarding the natural course of RCT onset and progression.

Does Margin Convergence Reverse Pseudoparalysis in Patients with Irreparable Rotator Cuff Tears?

BACKGROUND: Margin convergence has been shown to restore muscle tension in a cadaveric model of a rotator cuff tear. However, the clinical utility of this technique remains uncertain for patients with pseudoparalysis caused by an irreparable rotator cuff tear. QUESTIONS/PURPOSES: (1) For patients with massive irreparable rotator cuff tears, in what proportion of patients does margin convergence reverse pseudoparalysis? (2) In patients with massive irreparable rotator cuff tears, does margin convergence improve American Shoulder and Elbow Surgeons (ASES) scores? (3) What is the survivorship free from MRI evidence of retear after margin convergence? METHODS: Between 2000 and 2015, we treated 203 patients for pseudoparalysis with a rotator cuff tear. Pseudoparalysis was defined as active elevation less than 90° with no stiffness, which a physical therapist evaluated in the sitting position using a goniometer after subacromial injection of 10 cc lidocaine to eliminate pain. Of those, we considered patients who underwent at least 3 weeks of unsuccessful nonoperative treatment in our hospital as potentially eligible. Twenty-one percent (43 of 203) who either improved or were lost to follow-up within 3 weeks of nonoperative treatment were excluded. A further 12% (25 of 203) were excluded because of cervical palsy, axillary nerve palsy after dislocation or subluxation, and development of severe shoulder stiffness (passive shoulder elevation < 90°). Repair was the first-line treatment, but if tears were considered irreparable with the torn tendon unable to reach the original footprint after mobilizing the cuff during surgery, margin convergence was used. When margin convergence failed, the procedure was converted to hemiarthroplasty using a small humeral head to help complete the repair. Therefore, 21% (42 of 203) of patients treated with regular repair (18% [36 of 203]) or hemiarthroplasty (3% [6 of 203]) were excluded. That left 93 patients eligible for consideration. Of those, 13 patients were lost before the minimum study follow-up of 2 years or had incomplete datasets, and 86% (80 of 93) were analyzed (49 men and 31 women; mean age 68 ± 9 years; mean follow-up 26 ± 4 months). Seventy-six percent (61 of 80) were not evaluated in the last 5 years. We considered reversal of pseudoparalysis as our primary study outcome of interest; we defined this as greater than 90° active forward elevation; physical therapists in care measured this in the sitting position by using goniometers. Clinical outcomes were evaluated based on the ASES score from chart review, active ROM in the shoulder measured by the physical therapists, and the 8-month Kaplan-Meier survivorship free from MRI evidence of retear graded by the first author. RESULTS: Pseudoparalysis was reversed in 93% (74 of 80) patients, and improvement in ASES scores was observed at the final follow-up (preoperative 22 ± 10 to postoperative 62 ± 21, mean difference 40 [95% CI 35 to 45]; p < 0.01). The 8-month Kaplan-Meier survivorship free from MRI evidence of retear after surgery was 72% (95% CI 63% to 81%). There were no differences in clinical scores between patients with and without retears (intact ASES 64 ± 24, re-tear ASES 59 ± 10, mean difference 6 [95% CI -5 to 16]; p = 0.27). CONCLUSION: Margin convergence can be a good option for treating patients with pseudoparalysis and irreparable rotator cuff tears despite the relatively high retear rates. The proportion of pseudoparalysis reversal was lower in patients with three-tendon involvement. Further studies will be needed to define the appropriate procedure in this group. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Superior Capsular Reconstruction Provides Sufficient Biomechanical Outcomes for Massive, Irreparable Rotator Cuff Tears: A Systematic Review.

PURPOSE: To critically review the literature reporting biomechanical outcomes of superior capsular reconstruction (SCR) for the treatment of massive and/or irreparable rotator cuff tears. METHODS: A systematic review was performed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines using the PubMed, MEDLINE, and Cochrane Library databases in August 2020. Cadaveric studies were assessed for glenohumeral translation, subacromial contact pressure, and superior humeral translation comparing SCR with an intact cuff with reference to a torn control state. RESULTS: A total of 15 studies (142 shoulders) were included in our data analysis. SCR showed improvements in superior humeral translation, subacromial contact force, and glenohumeral contact force when biomechanically compared with the massive and/or irreparably torn rotator cuff. No statistically significant differences were found between SCR and the intact rotator cuff regarding superior humeral translation (standard mean difference [SMD], 2.09 mm vs 2.50 mm; P = .54) or subacromial contact force (SMD, 2.85 mPa vs 2.83 mPa; P = .99). Significant differences were observed between SCR and the intact cuff for glenohumeral contact force only, in favor of the intact cuff (SMD, 1.73 N vs 5.45 N; P = .03). CONCLUSIONS: SCR may largely restore static restraints to superior humeral translation in irreparable rotator cuff tears, although active glenohumeral compression is diminished relative to the intact rotator cuff. CLINICAL RELEVANCE: Investigating the biomechanical outcomes of SCR will help surgeons better understand the effectiveness of this treatment option.

Lateral acromioplasty cannot sufficiently reduce the critical shoulder angle if preoperatively measured over 40°.

PURPOSE: To investigate whether arthroscopic lateral acromion resection can sufficiently reduce the critical shoulder angle (CSA) without damaging deltoid muscle insertion. METHODS: Ninety patients who underwent arthroscopic rotator cuff (RC) repair were retrospectively analysed. According to the preoperative CSA, patients were categorized as Group I (CSA < 35°) and Group II (CSA ≥ 35°). Additional arthroscopic lateral acromion resection was performed in Group II. The CSA was measured 1 week postoperatively, while RC integrity and the deltoid attachment were assessed at 3, 6 and 12 months via ultrasound. Deltoid function was evaluated using the Akimbo test, in which patients place their hands on the iliac crest with abduction in the coronal plane and internal rotation of the shoulder joint while simultaneously flexing the elbow joint and pronating the forearm. RESULTS: Large and massive RC tears were more prevalent in Group II (p = 0.017). In both groups, the CSA reduction was statistically significant (Group I = 1°: range 0°-3°, Group II = 3.7°: range 1°-8°; p < 0.001). When the preoperative CSA was > 40°, the respective postoperative CSA remained > 35° in 83.3% of cases (p < 0.001). Final shoulder strength was correlated with the amount of CSA reduction (rho = 0.41, p = 0.002). The postoperative CSA was higher, but not significantly different (n.s.), in patients with re-torn (36°, range 32°-40°) than with healed RC (33°, range 26°-38°). No clinical detachment or hypotrophy of the deltoid was observed with the Akimbo test and ultrasound evaluation. CONCLUSIONS: Arthroscopic lateral acromion resection is a safe procedure without affecting deltoid muscle origin or function, and it is effective in significantly reducing the CSA. However, the CSA cannot always be reduced to < 35°, especially in patients with preoperative CSA values > 40°. LEVEL OF EVIDENCE: III.

Mobility Assessment of the Supraspinatus in a Porcine Cadaver Model Using a Sensor-Enhanced, Arthroscopic Grasper.

Tendon mobility is highly relevant in rotator cuff surgery. Objective data about rotator cuff mobility is rare. Tendon mobility still needs to be evaluated subjectively by the surgeon. This study aims to establish a porcine animal model for mobility analysis of the supraspinatus. In this context, we introduce a sensor-enhanced, arthroscopic grasper (SEAG) suitable for objective intraoperative measurements of tendon mobility in clinical praxis. Tendon mobility of 15 fresh porcine cadaver shoulders with artificial rotator cuff tears was evaluated using the SEAG. Mobility characteristics (load-displacement curves, maximum load, stiffness) were studied and inter- and intraobserver agreement (intraclass correlation coefficient (ICC)) were tested. Factors with a potential adverse effect (plastic deformation and rigor mortis) were also evaluated. All shoulders showed characteristic reproducible load-displacement curves with a nonlinear part at the start, followed by a linear part. Mean maximum load was 28.6 N ± 12.5. Mean stiffness was 6.0 N/mm ± 2.6. We found substantial interobserver agreement (ICC 0.672) and nearly perfect intraobserver agreement (0.944) for maximum load measurement. Inter- (0.021) and intraobserver (0.774) agreement for stiffness was lower. Plastic deformation and rigor mortis were excluded. The animal model demonstrates reliable and in vivo-like measurements of tendon mobility. The SEAG is a reliable tool for tendon mobility assessment.

Did the prevalence of suprascapular neuropathy in professional volleyball players decrease with the changes occurred in serving technique?

Objectives: Suprascapular neuropathy is more frequent in volleyball as compared to other overhead sports. This study aims to report the actual prevalence of suprascapular neuropathy among elite volleyball players. The hypothesis is that becoming jump topspin serves the most common serving technique, suprascapular neuropathy reduced its frequency. Methods: A total of 82 professional players were enrolled in the study. The presence of symptoms and the type of serve preferably performed were investigated. The strength and trophicity of the supraspinatus and infraspinatus muscles were evaluated. Patients with positive clinical findings underwent MRI of the shoulder. Results: The jump topspin serve was found to be the most popular type of serve both in males and females. At physical examination, 9% of the males and 12% of the females presented with infraspinatus muscle hypotrophy. Each case was accompanied by external rotation weakness. None of them complained of pain or reduced performance when they played. MRI confirmed infraspinatus muscle atrophy in all subjects. Conclusion: A lower prevalence of suprascapular neuropathy was found as compared with that previously reported in the 1980s and 1990s. A reduction in the popularity of the float serve seems to be a possible explanation. Thus, the jump topspin serve could be safe for suprascapular neuropathy and associated injuries in volleyball. The findings of this study should be considered by athletes and coaches for the prevention of activity-related injuries.

A classification for partial subscapularis tendon tears.

PURPOSE: The aim of the study was to analyze partial subscapularis tendon (SSC) tears and provide a descriptive classification. METHODS: The retrospective study included 50 patients with arthroscopically confirmed partial SSC tears. Internal rotation (IR) force measurements and IR ROM have been made and compared to the healthy contralateral side. Then the footprint of the SSC was routinely investigated by arthroscopy with standardized measurement of the bony footprint lesion. The partial tears were classified according to the mediolateral and craniocaudal extension of the rupture in the transverse and coronal plane, respectively. RESULTS: Partial SSC tears could be classified into split lesions (type 1, n = 11) and 3 further groups depending on the mediolateral peeled-off length of the bony footprint (type 2: < 10 mm, n = 20; type 3: 10-15 mm, n = 10; type 4: > 15 mm, n = 9). Type 2-4 could be further divided depending on the craniocaudal peeled-off length of the bony footprint (group A: < 10 mm, group B: 10-15 mm, group C: > 15 mm). Significantly decreased IR strength was shown for types 2-4 (p < 0.05) but not for split lesions as compared to healthy side. Types 1-4 showed significant decreased active IR ROM and all except type 3 (n.s.) which showed decreased passive IR ROM compared to the healthy side (p < 0.05). CONCLUSION: We present a novel classification for partial SSC tears for a more detailed and reproducible description. This can help to improve the current knowledge about the appropriate treatment. It could be shown that partial tears of the subscapularis can have an impact on IR strength and motion. LEVEL OF EVIDENCE: III.

Anterior rotator cable disruption does not affect outcomes in rotator cuff tear with subscapularis involvement.

PURPOSE: The purpose of this study was to compare clinical and radiological outcomes after arthroscopic repair of two different rotator cuff tear configurations: anterosuperior rotator cuff tear and rotator cuff tears with subscapularis involvement. It was hypothesized that, although both tear configurations would show significant improvement in clinical outcomes after arthroscopic repair, the rotator cuff tears with subscapularis involvement where the anterior rotator cable maintains its integrity would have better clinical outcomes and structural integrity. METHODS: This study included 226 patients who underwent arthroscopic repair of anterosuperior rotator cuff tears (n = 107, group A) and rotator cuff tears with subscapularis involvement (n = 119, group B). The visual analog scale (VAS) pain score, subjective shoulder value (SSV), American Shoulder and Elbow Surgeons (ASES) score, University of California at Los Angeles (UCLA) shoulder score, and active range of motion (ROM) were assessed. Modified belly press test was performed to assess the strength of the subscapularis muscle. Cuff integrity was evaluated using magnetic resonance arthrography or computed tomographic arthrography at 6 months after operation. RESULTS: At 3-year follow-up, the VAS score, SSVs, ASES scores, UCLA shoulder scores, active ROM, and modified belly press test showed significant improvement in both groups (p < 0.001). However, these improvements showed no statistical significance between the two groups. On follow-up radiologic evaluations, no significant difference in re-tear rates between group A (25 of 107, 23.4%) and group B (23 of 119, 19.3%) was observed. CONCLUSIONS: The presence of anterior cable involvement of the anterosuperior rotator cuff tear did not affect postoperative clinical outcomes and re-tear rate compared to rotator cuff tears with subscapularis involvement where the anterior cable integrity was maintained, although the anterosuperior rotator cuff tear was associated with more significant preoperative supraspinatus fatty infiltration. Therefore, the present study determined that it would not be necessary to differentiate treatment protocols between these patterns. LEVEL OF EVIDENCE: Level III.